Brightness (ANSI Lumens): The #1 Spec
Manufacturers love to list "LED lumens" or "lux" — both are inflated marketing numbers. The only brightness spec that matters is ANSI lumens, measured by a standardized test. For a dark room, you need at least 300 ANSI lumens. For a dimly lit living room, 500+. Outdoor use at dusk? 800+ ANSI lumens minimum.
Most projectors under $150 claim "5,000 lumens" but actually output 150–250 ANSI lumens — fine for a dark bedroom wall at 60 inches, useless for anything bigger or brighter. We test every projector with a lux meter at 100 inches. If it can't hit 30 lux at that size, it doesn't make our list.
Native Resolution vs. "Supported" Resolution
This is where budget projectors trick buyers. A listing might say "1080p supported" — meaning it accepts a 1080p input signal but downscales it to the projector's native resolution, which could be 480p (854×480). Always check the native resolution spec.
720p (1280×720) is the minimum for enjoyable movie watching. 1080p (1920×1080) is ideal for most portable use. True 4K portable projectors exist (Samsung The Freestyle, XGIMI Halo+) but start at $600+. For most people, a good 1080p portable projector at 300–500 ANSI lumens delivers the best value.
Throw Ratio: How Far Back It Needs to Sit
Throw ratio tells you how far from the wall the projector must sit to create a given image size. A 1.2:1 ratio means at 1.2 meters away, you get a 1-meter-wide image (about 46 inches). Most portables range from 1.1:1 to 1.5:1.
Shorter ratios (1.1:1) are better for small rooms — you can get a 100-inch image from about 8 feet back. Longer ratios need more space. Auto-keystone and auto-focus are must-haves for portable use; manual adjustment every time you move the projector is a dealbreaker.
Battery Life & Audio
Built-in batteries range from 1.5 to 3.5 hours — enough for most movies if the projector claims 2.5+ hours. Under 2 hours means you'll need external power for anything longer than a sitcom episode. Built-in speakers are universally mediocre; budget for a Bluetooth speaker. Most portable projectors support Bluetooth audio output.